The purpose of this guide is to provide simple factsheets on priority invasive alien pests that currently threaten plant health, human health and/or biodiversity in the Pitcairn Islands (Pitcairn, Henderson, Ducie and Oeno Islands), a UK Overseas Territory located in the southern Pacific Ocean. It also identifies the main pathways of introduction so that biosecurity inspections can be targeted. The guide is intended to be used by those working in biosecurity, and by all those interested in preserving the unique environments and biodiversity found in the Pitcairn Islands.

The effects of alien invasive species on biodiversity have been described as “immense, insidious and usually irreversible” (IUCN 2000). There is no doubt that invasive species can cause severe economic and ecological damage (Mack et al. 2000). They may soon surpass habitat loss as the main cause of ecological disintegration globally (Vitousek et al. 1997, Chapin et al. 2000) and are probably already the main cause of extinctions in island ecosystems.